1,676 research outputs found
Moderate beer consumption does not change early or mature atherosclerosis in mice
BACKGROUND: Although the consumption of wine in particular has been associated with a lower risk of atherothrombotic cardiovascular disease, systematic reviews differ as to the relative protective effect of beer, wine and spirits. Two previous studies showed that red wine reduces fatty streak formation (early atherosclerosis) but not mature atherosclerosis in apolipoprotein (apo) E-deficient (apoE-/-) mice. AIM OF THE STUDY: To determine whether a moderate beer intake would affect early and mature atherosclerotic lesion formation using control C57BL/6 and apoE-/- mice, respectively, as models. METHODS: Control C57BL/6 and apoE-/- mice were randomized to receive either water, ethanol, mild beer, dark beer or ethanol-free beer. The level of beer was designed to approximate the alcohol intake currently believed to be beneficial in reducing human vascular risk. Control C57BL/6 mice were fed a Western diet for 24 weeks, and apoE-/- mice a chow diet for 12 weeks. At the end of the trial period, mice were euthanized and atherosclerotic lesions quantified. Plasma lipid concentrations were also measured. RESULTS: The amount of atherosclerosis and average number of lesions in the proximal aortic region did not differ among groups in control C57BL/6 mice (p = 0.32 and p = 0.29, respectively) and apoE-/- mice (p = 0.19 and p = 0.59, respectively). No consistent differences were observed in plasma lipid and lipoprotein concentrations among water, ethanol and beer groups. CONCLUSIONS: Moderate beer consumption does not change the development of early or mature atherosclerosis in mice. Our findings do not support the hypothesis of an anti-atherogenic effect of beer. Other potential protective actions of moderate beer consumption such as plaque stabilization, a reduction in plaque intrinsic thrombogenicity, or a reduction in the systemic propensity to thrombosis, remain to be studied
Crack-Like Processes Governing the Onset of Frictional Slip
We perform real-time measurements of the net contact area between two blocks
of like material at the onset of frictional slip. We show that the process of
interface detachment, which immediately precedes the inception of frictional
sliding, is governed by three different types of detachment fronts. These
crack-like detachment fronts differ by both their propagation velocities and by
the amount of net contact surface reduction caused by their passage. The most
rapid fronts propagate at intersonic velocities but generate a negligible
reduction in contact area across the interface. Sub-Rayleigh fronts are
crack-like modes which propagate at velocities up to the Rayleigh wave speed,
VR, and give rise to an approximate 10% reduction in net contact area. The most
efficient contact area reduction (~20%) is precipitated by the passage of slow
detachment fronts. These fronts propagate at anomalously slow velocities, which
are over an order of magnitude lower than VR yet orders of magnitude higher
than other characteristic velocity scales such as either slip or loading
velocities. Slow fronts are generated, in conjunction with intersonic fronts,
by the sudden arrest of sub-Rayleigh fronts. No overall sliding of the
interface occurs until either of the slower two fronts traverses the entire
interface, and motion at the leading edge of the interface is initiated. Slip
at the trailing edge of the interface accompanies the motion of both the slow
and sub-Rayleigh fronts. We might expect these modes to be important in both
fault nucleation and earthquake dynamics.Comment: 19 page, 5 figures, to appear in International Journal of Fractur
Variations of training load, monotony, and strain and dose-response relationships with maximal aerobic speed, maximal oxygen uptake, and isokinetic strength in professional soccer players
This study aimed to identify variations in weekly training load, training monotony, and training strain across a 10-week period (during both, pre- and in-season phases); and to analyze the dose-response relationships between training markers and maximal aerobic speed (MAS), maximal oxygen uptake, and isokinetic strength. Twenty-seven professional soccer players (24.9±3.5 years old) were monitored across the 10-week period using global positioning system units. Players were also tested for maximal aerobic speed, maximal oxygen uptake, and isokinetic strength before and after 10 weeks of training. Large positive correlations were found between sum of training load and extension peak torque in the right lower limb (r = 0.57, 90%CI[0.15;0.82]) and the ratio agonist/antagonist in the right lower limb (r = 0.51, [0.06;0.78]). It was observed that loading measures fluctuated across the period of the study and that the load was meaningfully associated with changes in the fitness status of players. However, those magnitudes of correlations were small-to-large, suggesting that variations in fitness level cannot be exclusively explained by the accumulated load and loading profile
Discovering privileged topologies of molecular knots with self-assembling models
Despite the several available strategies to build complex supramolecular constructs, only a handful of different molecular knots have been synthesised so far. Here, in response to the quest for further designable topologies, we use Monte Carlo sampling and molecular dynamics simulations, informed by general principles of supramolecular assembly, as a discovery tool for thermodynamically and kinetically accessible knot types made of helical templates. By combining this approach with the exhaustive enumeration of molecular braiding patterns applicable to more general template geometries, we find that only few selected shapes have the closed, symmetric and quasi-planar character typical of synthetic knots. The corresponding collection of admissible topologies is extremely restricted. It covers all known molecular knots but it especially includes a limited set of novel complex ones that have not yet been obtained experimentally, such as 10124 and 15n41185, making them privileged targets for future self-assembling experiments
Pharmacogene sequencing of a Gabonese population with severe Plasmodium falciparum malaria reveals multiple novel variants with putative relevance for antimalarial treatment.
Malaria remains one of the most deadly diseases in Africa, particularly for children. While successful in reducing morbidity and mortality, antimalarial treatments are also a major cause of adverse drug reactions (ADRs). Host genetic variation in genes involved in drug disposition or toxicity constitutes an important determinant of ADR risk and can prime for parasite drug resistance. Importantly however, the genetic diversity in Africa is substantial and thus genetic profiles in one population cannot be reliably extrapolated to other ethnogeographic groups. Gabon is considered a high-transmission country with more than 460,000 malaria cases per year. Yet, the pharmacogenetic landscape of the Gabonese population or its neighboring countries has not been analyzed. Using targeted sequencing, we here profiled 21 pharmacogenes with importance for antimalarial treatment in 48 Gabonese pediatric patients with severe Plasmodium falciparum malaria. Overall, we identified 347 genetic variants of which 18 were novel and each individual was found to carry 87.3±9.2 SD variants across all analyzed genes. Importantly, 16.7% of these variants were population-specific, highlighting the need for high-resolution pharmacogenomic profiling. Between one in three and one in six individuals harbored reduced activity alleles of CYP2A6, CYP2B6, CYP2D6 and CYP2C8 with important implications for artemisinin, chloroquine and amodiaquine therapy. Furthermore, one in three patients harbored at least one G6PD deficient allele, suggesting considerably increased risk of hemolytic anemia upon exposure to aminoquinolines. Combined, our results reveal the unique genetic landscape of the Gabonese population and pinpoint the genetic basis for inter-individual differences in antimalarial drug response and toxicity
Results from PAMELA, ATIC and FERMI : Pulsars or Dark Matter ?
It is well known that the dark matter dominates the dynamics of galaxies and
clusters of galaxies. Its constituents remain a mystery despite an assiduous
search for them over the past three decades. Recent results from the
satellite-based PAMELA experiment detect an excess in the positron fraction at
energies between 10-100 GeV in the secondary cosmic ray spectrum. Other
experiments namely ATIC, HESS and FERMI show an excess in the total electron
(\ps + \el) spectrum for energies greater 100 GeV. These excesses in the
positron fraction as well as the electron spectrum could arise in local
astrophysical processes like pulsars, or can be attributed to the annihilation
of the dark matter particles. The second possibility gives clues to the
possible candidates for the dark matter in galaxies and other astrophysical
systems. In this article, we give a report of these exciting developments.Comment: 27 Pages, extensively revised and significantly extended, to appear
in Pramana as topical revie
Possible mechanisms of host resistance to Haemonchus contortus infection in sheep breeds native to the Canary Islands
Haemonchus contortus appears to be the most economically important helminth parasite for small ruminant production in many regions of the world. The two sheep breeds native to the Canary Islands display distinctly different resistant phenotypes under both natural and experimental infections. Canaria Hair Breed (CHB) tends to have significantly lower worm burden and delayed and reduced egg production than the susceptible Canaria Sheep (CS). To understand molecular mechanisms underlying host resistance, we compared the abomasal mucosal transcriptome of the two breeds in response to Haemonchus infection using RNAseq technology. The transcript abundance of 711 and 50 genes were significantly impacted by infection in CHB and CS, respectively (false discovery rate <0.05) while 27 of these genes were significantly affected in both breeds. Likewise, 477 and 16 Gene Ontology (GO) terms were significantly enriched in CHB and CS, respectively (P < 1.0 × 10(−4)). A broad range of mechanisms have evolved in resistant CHB to provide protection against the parasite. Our findings suggest that readily inducible acute inflammatory responses, complement activation, accelerated cell proliferation and subsequent tissue repair, and immunity directed against parasite fecundity all contributed to the development of host resistance to parasitic infection in the resistant breed
Leptogenesis from loop effects in curved spacetime
We describe a new mechanism -- radiatively-induced gravitational leptogenesis -- for generating the matter-antimatter asymmetry of the Universe. We show how quantum loop effects in C and CP violating theories cause matter and antimatter to propagate differently in the presence of gravity, and prove this is forbidden in flat space by CPT and translation symmetry. This generates a curvature-dependent chemical potential for leptons, allowing a matter-antimatter asymmetry to be generated in thermal equilibrium in the early Universe. The time-dependent dynamics necessary for leptogenesis is provided by the interaction of the virtual self-energy cloud of the leptons with the expanding curved spacetime background, which violates the strong equivalence principle and allows a distinction between matter and antimatter. We show here how this mechanism is realised in a particular BSM theory, the see-saw model, where the quantum loops involve the heavy sterile neutrinos responsible for light neutrino masses. We demonstrate by explicit computation of the relevant two-loop Feynman diagrams how the size of the radiative corrections relevant for leptogenesis becomes enhanced by increasing the mass hierarchy of the sterile neutrinos, and show that for realistic phenomenological parameters this mechanism can generate the observed baryon-to-photon ratio of the Universe
Endocrine therapy for breast cancer: a model of hormonal manipulation
Oestrogen receptor (ER) is the driving transcription factor in 70% of breast cancer. Endocrine therapies targeting the ER represent one of the most successful anticancer strategies to date. In the clinic, novel targeted agents are now being exploited in combination with established endocrine therapies to maximise efficacy. However, clinicians must balance this gain against the risk to patients of increased side effects with combination therapies. This article provides a succinct outline of the principles of hormonal manipulation in breast cancer, alongside the key evidence that underpins current clinical practice. As the role of endocrine therapy in breast cancer continues to expand, the challenge is to interpret the data and select the optimal strategy for a given clinical scenario
Evaluation of dog owners' perceptions concerning radiation therapy
<p>Abstract</p> <p>Background</p> <p>External radiation therapy (RT) has been available for small animals in Sweden since 2006. This study was designed to obtain information on owner experiences and perceptions related to RT of cancer in their dogs. Another survey was used to determine the attitudes about use of RT in a group of Swedish veterinarians. Their responses were analyzed and compared to their level of knowledge of oncology and RT.</p> <p>Methods</p> <p>Owners of all dogs (n = 23) who had undergone RT for malignancy at Jönköping Small Animal Hospital between March 2006 to September 2007 were interviewed. A questionnaire was given to a selected group of veterinarians.</p> <p>Results</p> <p>All 23 owners responded. All owners thought that their dog did well during RT and most that their dog was also fine during the following phase when acute RT-related skin reactions occur and heal. Three owners stated that their dog had pain that negatively impacted quality of life because of radiation dermatitis. Five owners reported that RT positively impacted quality of life of the dog during the first weeks after RT because palliation was achieved. The owners were not disturbed by the efforts required of them. All but one owner (22 of 23) stated that they would make the same decision about RT again if a similar situation occurred. The most important factor for this decision was the chance to delay occurrence of tumour-related discomfort. The chance for cure was of less importance but still essential, followed by expected side effects. Time commitments, travel, number of treatments required and financial cost; all had low impact. The veterinarian survey showed that less background knowledge of small animal oncology/RT was associated with more negative expectations of RT for small animals.</p> <p>Conclusion</p> <p>The results show that for these owners, RT was a worthwhile treatment modality and that the discomfort for the dog was manageable and acceptable relative to the benefits. Improved continuing education about small animal RT in Sweden will likely result in increased evidence-based and positive treatment recommendations concerning RT by veterinarians.</p
- …